Xantia 1.9TD, oil in Water tank,HG busted?, was Oil cooler

masood_ilyas · Post by **masood_ilyas** » 13 May 2008, 00:40

This query relates to a 1999 Citroen Xantia 1.9TD LX automatic with 145K miles on the clock.

It was a hot day so decided to make sure the coolant level was correct before taking the car out for a run in the west country.
On taking the cap off, I was horrified to see a black oily sludge sitting at the top of water tank.
Last level check was done about a month ago so it is relatively a recent failure, perhaps it has been like this for the last 300 miles
Searched our forum and read that it might be the oil heat exchanger which is located just where the engine oil filter sits.
Head gasket being more difficult so decided to eliminate the cooler by replacing with one from scrappy. On removing it I applied air pressure on one input of the heat exchanger and blocked the other end, to my surprise it happily withstood the pressure of 20 lbs with no sign or sound of leak, I did not dare increase the pressure any further in case it really did damage it. Can I assume from this that the cooler is innocent and must now look for the failure else where possibly even prepare myself for a head gasket change.

Am I being too hasty in condemning the head gasket? Has any one else come across this before.
Any advice or suggestion will be gratefully received.

Masood ILYAS

AndersDK · Post by **AndersDK** » 13 May 2008, 00:52

Some oily sludge in the coolant header is by no means a sure HG failure indicator.
Most likely its from previous repairs where some grease or oil got in contact with the wet side of the system.

IF the HG is blown, THEN the coolant system WILL 100% surely overpressure - pressing out the coolant fluid during a normal drive.

Its still possible to have a leak in the oil cooler, and it wont help you sourcing another one from a scrapyard. They are notoriously UN-reliable as regards corrosion.
They can still leak a wee bit of oil out into the cooling system despite your testing with air.
Check the engine oil too. It WILL have traces of coolant/water if the oil cooler is leaking.

Post by **CitroJim** » 13 May 2008, 20:05

As Anders says, the first indication of HG failure is pressurisation and loss of coolant. The cooling system very, very rarely becomes contaminated with oil as a result of a failed head gasket.

The oil cooler is still suspect I think. a 20psi test on the water side is not conclusive. On the oil side you have far higher pressures; the XUD runs very high oil pressure and it will not take much of a weakness for a small amount of oil to find its way into the coolant. It only takes a tiny amount of oil to get into the coolant and make rather a mess.

I don't recommend you bypass the cooler on a permanant basis as it is pretty much essential for the health of the engine but you could bypass the water side for a test.

If you are consuming no water and cannot see any streams of bubbles in the expansion tank with the cap off then you can be fairly sure the head gasket is OK.

Post by **Peter.N.** » 13 May 2008, 22:28

Once you get oil in the cooling system its very difficult to get rid of, so even if you think you have cured it, itwill be a while before you can tell. I had an XM a few years ago with the same problem, even after bypassing the oil cooler and fitting a new head gasket, the leak continued, I suspect there was a crack somewhere, but the good news is that I ran the car for another year or so and it never got any worse.

I agree with citroenjm, 20 psi is not really enough, the oil pressure can be 60 or 70 psi and I have heard of oil coolers on the 2.5 XM engine which will leak in one direction but not the other, failing that, I think the head gasket would be next favourite.

masood_ilyas · Post by **masood_ilyas** » 13 May 2008, 23:04

Thanks Anders, Citrojim and Peter N.
It is a relief to read that it is not the HG.
I had no idea that the oil pressure can be as high as 70, no wonder my 20psi air pressure test was not thorough enough to rule out the heat exchanger conclusively.
I wil take Anders advice and give the scrap yard a miss and see my local stealer intead. Any idea what to expect to pay for this?.

I will update this thread when there is any development

Masood

masood_ilyas · Post by **masood_ilyas** » 14 May 2008, 12:28

The main dealer tell me that this cooler will cost £193. Ouch, and ouch again. There are no other options but to go to him, ouch.
Peter.N mentions it takes a long time to clear the oil from the cooling circuit.
Can I use half a dish washer tablet or a drop of fairy liquid to accelerate the oil removal, or is it not advisable. I am concerned the foaming might cause air locks and cause more damage in the process.
What is the opinion of the forum members on using decreasing agents.

Thanks you all for your advice.

Masood

Post by **CitroJim** » 14 May 2008, 12:46

At that price Masood, it has to be worth risking one from a scrapper!

The price is a bit shocking for such a ubiqutous part. Millions of XU and XUD engines had then.

As for flushing out the oil, I can't make a recommendation but one thing I'd not do is use a dishwasher tablet. They're abrasive and what worries me is that the abrasive particles may wear holes in the heater matrix.

I base that on a 205 I had that ate heater matrixes for breakfast. Turned out the engine had run on plain water for some time and there was rock and scale in the expansion tank and hoses. Over time, this rock, in suspension in the water, wore holes in the thin alloy pipes in the matrix!

The last thing you want to do is risk matrix damage, given the task of replacing them!

Post by **myglaren** » 14 May 2008, 13:32

Use a proper cooling system flush, The washing tablets will create tons of foam and the cooling won't work. Very bad news.

Try and attach a hosepipe and reverse-flush it till all the visible gunk is out, then run it with a dedicated flushing agent, the reverse flush it again.

Do it fairly quickly to avoid a lot of air getting in, which will promote corrosion (rust, anyway) internally.

If you can, boil the water prior to refilling the system, it drives out the dissolved air in it and in hard water areas will solidify calcium in the water.
Have you tried alternative suppliers for the oil cooler? The likes of GSF and Europarts?

mbunting · Post by **mbunting** » 14 May 2008, 14:25

Don't panic yet - I notice you have an auto box - what's the auto fluid level like - noticed any rough gearchanges lately ?

I think the auto transmission also has a cooler - it may be this leaking auto transmission fluid, rather an actual oil - you don't mention about checking the oil level...

AndersDK · Post by **AndersDK** » 14 May 2008, 18:17

Yes - Matt is right - the autobox has a similar cooler. Different design though.
Problem could be here intead.

Just checked the pricelevel at DK dealers. £320 (incl 25%vat) for the engine oil cooler

Insane

Pricetag is almost the same at Peugeot dealers

masood_ilyas · Post by **masood_ilyas** » 14 May 2008, 18:26

Citrojim you are right it is worth a punt but I am split on taking your advice or heeding Anders' warning on UN reliable coolers, on this occasion I might just lean on the side of caution (sign of growing old) and bear the expense as I would hate to be revisiting this one during the cold winter days.

Maglaren and Citrojim thank you, point taken about the use of cleaning agents, thanks for stopping me from making bigger mistakes. I shall just reverse flush it with a feed of domestic hot water ( about 50 deg centigrade) from the Worcester Boiler! it fills the normal baths in no time so a radiator should be a piece of cake.

Mbunting thank you for pointing out another possibility, alas this car has a modern electronic AL4 automatic gear box it is supposed to be "sealed for life" and has it own separate cooler which is not fed with any of the radiator water so I don't think it is likely to be the gearbox. The gear changes are fine. Being sealed for life Citroen did not provide a dip stick for measuring oil level on these boxes.

Thank you all once again.

Masood

DickieG · Post by **DickieG** » 14 May 2008, 19:54

masood_ilyas wrote:alas this car has a modern electronic AL4 automatic gear box it is supposed to be "sealed for life" and has it own separate cooler which is not fed with any of the radiator water so I don't think it is likely to be the gearbox. The gear changes are fine. Being sealed for life Citroen did not provide a dip stick for measuring oil level on these boxes.

Take a look under the air filter and you should find

a dipstick

The box isn't sealed for life and regular fluid changes are important if you want the box to last beyind 100k miles.

masood_ilyas · Post by **masood_ilyas** » 14 May 2008, 20:06

Just as I was typing my last update, Anders' latest comment was added.
Matt and Anders you are right, this car does have a gearbox oil cooler that is fed from the main cooling circuit, my understanding was incorrect. Having had the gearbox recently refurbished the gearbox was furthest away from my thoughts. As you and Anders have pointed out it could be this. The sludge however I have noticed is heavy and dark like engine oil, gearbox oil is a bit lighter and brownish so it may still be the main engine cooler.

Back to the drawing board, looks like I have to eliminate two coolers now.!
I can briefly by pass the engine cooler and check for leakage, perhaps do the same for the autobox.

Masood

lolingram · Post by **lolingram** » 17 May 2008, 11:57

Use a proper cooling system flush, The washing tablets will create tons of foam and the cooling won't work. Very bad news.

For what it is worth... my Xant HDi developed the same symptoms - oil in the water; LOTS - and it was the oil/water heat interchanger ('cooler') under the filter. I obtained one from a scrapper for €20 Euros, after testing it at 7 bars (105psi), and this has worked out just fine.

Finish brand dishwasher tabs do NOT foam at all, and do a good quick job. I flushed my system all ways after running a few miles with the tabs THREE TIMES; then once more a week later with plain water before finally re-filling with antifreeze. It is a good idea to watch the big hoses afterwards - mine went slightly softer, but all is currently OK.

Hope this helps - don't be scared about using a secondhand heat exchanger - they don't leak that often.

lexi · Post by **lexi** » 17 May 2008, 12:16

Only thing I would say with dishwasher tablets is that they usually contain Caustic Soda....which is a no no. May be ok if you get it in and out quick. Common problem with Auto coolers in Radiator is that cooler can block after 100k with fine metal from bands of Auto Box. This leads to restricted fluid flow and overheating failures.

A way around it sometimes is to bypass and fit a Mocal type.......may not apply here though.